1. Field of the Invention
The invention relates to a flexible printed circuit (FPC), and more particularly a FPC applied in a display device.
2. Description of the Related Art
FIG. 1a is a schematic diagram of a conventional FPC applied in a display device. FPCs 131˜13n are coupled between a display panel 11 and a printed circuit board (PCB) 12 for transmitting signals therebetween. Display panel 11 and PCB 12 respectively comprise a plurality of connection lines (not shown) for connecting FPCs 131˜13n. FPCs 131˜13n respectively comprise metal lines L1˜L4. One terminal of the metal lines L1˜L4 is coupled to connection lines of display panel 11 and the other terminal of metal lines L1˜L4 is coupled to connection lines of PCB 12.
FIG. 1b shows a cross section along line A-A of FIG. 1a. Since the connection methods applied among FPCs 131˜13n, display panel 11, and PCB 12 are the same, a connection method applied among FPC 131, display panel 11, and PCB 12 is given as an example.
First, Anisotropic Conductive Film (ACF) 14 is disposed among display panel 11, PCB 12, and FPC 131. Next, ACF 14 is heated to increase adhesion capability and pressure is than exerted on display panel 11, PCB 12, and FPC 131 to electrically connect connection line L5 and metal line L1, and connection line L6 and metal line L1.
Metal line L1 and connection lines L5, L6 are generally constituted by copper, however, the adhesion capability between copper and ACF 14 is poor. Thus, display panel 11 and PCB 12 are not firmly connected to FPC 13.
To prevent the adhesion problem, the duration that pressure is exerted is increased to increase the adhesion capability between metal line L1 and connection line L5, and metal line L1 and connection line L6. When the pressure duration is increased, the manufacture timing of the display device increases.